UPDATED MAY 24, 2013 AT 1900 UTC (2 p.m. CDT). An M5-class solar flare on May 22, 2013 released a coronal mass ejection or CME. which has – as expected – now delivered a glancing blow to Earth’s magnetic field. The Advanced Composition Explorer (ACE) spacecraft – used by the Space Weather Prediction Center to provide warnings of these events – detected it beginning at about 1735 UTC (12:35 p.m. CDT) today. The Space Weather Prediction Center says to look for G1 (minor) geomagnetic storm levels over the next 24 hours. The estimate is for a 55% chance of polar geomagnetic storms in response to the strike. Aurora alert at high latitudes. Visit the Space Weather Prediction Center here for more updates.
Activity on the sun’s surface gives us on Earth the most spectacular light show known to man: the aurora borealis or northern lights. They are bands of light, caused by charged solar particles’ interaction with Earth’s magnetic field. They glow, ripple and enchant those those lucky enough to see the phenomenon with their own eyes. Witnessing the aurora borealis is an experience not to miss. However, sightings are never guaranteed. Many factors can have an impact on whether the lights will appear. We’ve answered some of the most commonly asked questions, below.
How do I know when to look for the northern lights? Good news. The sun itself will make the announcement. Aurorae are the result of solar activity, where colossal storms take place on the sun’s surface. Sometimes during these storms, coronal mass ejections (CMEs) – charged particles from the sun – are released. If the solar storm erupts in such a way that the resulting CME heads toward Earth, the likelihood of seeing an aurora increases. It takes several days for the charged particles to cross from the sun to Earth, so there is plenty of warning. When the charged particles arrive, they interact with Earth’s magnetic field, creating what is known as a geomagnetic storm. To what extent these charged particles will light up the night sky depends on a variety of factors including the strength of the CME plus whether it struck Earth’s magnetic field directly, or just delivered a glancing blow.
Spaceweather.com is a reliable and readable source of information about activity on the sun. Meanwhile, a great way to stay informed about the possibility of seeing an aurora on any given night is to access one of the numerous aurora alert websites: follow this link to find a list of aurora alert sites. Check them out when you get a chance; some update their forecasts live on Twitter.
Those keen to discover more about Earth’s magnetic field, meanwhile, might like to check out SAMNET, the sub-auroral magnetometer network from Lancaster University.
How far south can I see the aurora borealis tonight? In general, the farther north you go, the greater the chances of seeing the northern lights. Alaska, northern Canada, Iceland, Greenland and Scandinavia are places where they’re often seen, but, you’ll be pleased to hear, the lights can on occasion extend down to lower latitudes. In the instance of very high geomagnetic activity, they lights can be seen as far south as England, the northern and even the southern U.S. (a sighting was even apparently once reported near the Mexican border), Northern Germany and Poland.
These more southerly sightings of the northern lights are rare, but as and when a strong solar storm occurs, you might be lucky enough to see the lights fairly far south.
Othewise, for some real-time aurora tracking, try Aurora Spy’s live data and aurora web cams page.
Will a full moon affect my ability to see the northern lights? Usually not. Naturally, a sky washed with bright moonlight won’t be as dark as it might otherwise be and thus the contrast between the aurora and night sky background won’t be as great. But only the very weakest aurorae will be completely drowned by the light of a full moon. Even in full moonlight, strong northern lights can still be seen clearly and photographed. In fact, LightsOverLapland.com photographer Chad Blakley, who regularly takes shots from the Abisko Aurora Sky Station in Swedish Lapland, has said that some of his best northern lights photographs have been taken when there was a full moon. For proof, see this earlier EarthSky article and marvel at the pictures that were snapped during a full moon.
What happens if it’s cloudy? The rule of thumb is, if you can see the stars, you can see the Northern Lights. Essentially, if the cloud cover is ‘thin’ enough not to conceal the twinkling stars, it shouldn’t make much difference. Thick cloud hovers underneath the aurora, so yes, it would block any sightings, unfortunately.
Can you hear the aurora? While not a concern, this is a frequently asked question. And the answer is … we can’t be sure. Many people say they have heard a sound when witnessing the lights, but the upper atmosphere, according to the University of Alaska, is too thin to carry sounds waves. Plus the aurora itself is too far away. Yet still observers describe whistling, bristling, swooshing sound. The only way to know is to experience the aurora borealis for yourself!
About the Author: Brand Journalist and travel-obsessive Elizabeth Smythe writes this post on behalf of northern lights holiday specialists Weekend a la Carte. Check them out more insights and guides into this most magical of wonders.
Bottom line: Answers to commonly asked questions about seeing one of nature’s wonders: the aurora borealis or northern lights. Updated May 24, 2013 when a CME delivered a glancing blow to Earth’s magnetic field, providing an opportunity for possible high-latitude auroras.